Fuse for mines or the like



Feb. 4, 1930. H. GRUBER FUSE FOR mums OR THE LIKE Filed July 28; 1928 R TT'QR KEYS Patented Feb. 4, 1930' .HANS GRUBER, OF MUHLDORF, GERMANY FUSE FOB, MINES OR THE LIKE Application; filed July 28, .1928. Serial No. 296,063, and in Germany January 12, 1927.

The present invention relatesto a novel fuse for mines or the like which may be detonated both by a pull off or a shearing action.

Fuses for mines have hitherto been known which cause detonation when a so-called check or safety pin is either drawn out or pressed down. During transport, however, the known'fuses require, for the sake of safety, yet another safety device, which usually takes the form of a screw, between the percussion pin and the ignition cap. \Vhen now the said safety device is removed to render the fuse capable of operation the latter is no longer sufliciently protected against moisture and may even spoil while in position for this reason/ Furthermore in such fuses the percussion pin is at the same time a pressure pin. If, therefore, the fuse is to be actuated by a pressure of any kind, for example, by the weight of a vehicle or the like, the weight of the latter must act directly upon the percussion pin itself to which end the latter projects freely above the fuse housing. Since,

however, the percussion pin is comparatively speaking very thin a separate broad pressure plate must be mounted thereon in order to obtain a rather more certain action. A further defect of such fuses resides in the fact that there is always a point liable to leakage where the percussion pin projects out from the fuse housing and it is consequently easily possible for the percussion pin to rust in.

The present invention, which has as its object to eliminate these defects, consists in a'rranging the percussion pin completely inside a fuse head or shearing head serving at the same time as a pressure plate and in securing said pin in the safety position by means of a plurality of pins passing through said percussion pin. As a result the penetration of moisture into the fuse is impossible and the provision of a separate pressure plate on the fuse is no longer essential. There are a plurality of safety actions on the fuse.

Two embodiments of the invention are illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is an elevational view of one form of fuse with a bayonet connection shown in the unsafe position.

Fig. 2 a similar View of the fuse with the bayonet connection in the safe position and the fuse head screwed out from the fuse body, f Fig. 3 is a longitudinal section through the use, I

Fig. 4 a section through the fuse head,

Fig. 5 a section on the line AA of Fig. 2,

Fig. 6 a longitudinal section through the percussion pin,

Fig. 7 a section on the line 13-13 of Fig. 6,

Fig. 8 a longitudinal section through another constructional form of fuse in the safe position,

Fig. 9 an elevational view of the same fuse in the unsafe position, and

Fig. 10 a section of the percussion pin of the fuse illustrated in Fig. 8.

In the fuse shown in Figs. 1-7 the percussion pin 2 loaded with the pressure of a spring 1 is arranged completely inside the fuse or shearing head 3 which serves at the same time as'a pressure plate, in order to prevent the inward penetration of moisture. The percussion pin 2 is also located inside the fuse body which consists of the two cylindrical portions 4 and 5 screwed together. Theouter part 5 of the fuse body carries the supporting means 6 for the fuse cap 7. On operation of the fuse said cap is caused to explode by impact of the point 8 of the percussion pin. The fuse may be screwed to a mine hand-grenade, projectile or the like with the aid of the thread 17 providedatthelowerendof the supporting means 6. Three pins 9, 10 and 11 are passed through the percussion pin 2, the first of which, 9, serves merely as a check or safety pin, the second, 10, as will be further described, both as a check pin and also as a part of a first bayonet connection and the third, 11, merely as a part of a second bayonet connection. The check pins 9 and 10 are also passed through the fuse or shearing head 3 which is also provided with the slots 12, 13 for the bayonet connections. The check pin or shearing pin 10, moreover, passes through the part 4 of the fuse body. It will be explained below how the pins 9-11 render the fuse safe or unsafe with the aid of the bayonet connections. 7

As illustrated in Figs. 2 and the bayonet connections are in the safe position. The shearing pin 'is located in the right hand corner of the bayonet slot 12 and at the same time forms one part of a first bayonet con- 10. If now the shearing pin 10 is removed then the percussion pin 2 can only move downwardly a short distance by reason of the action of the spring 1 until the pin 11 bears with its projecting ends on the lower surfaces 14 (Figs. 3 and 4:) of the bayonet connection 13. Consequently the fuse is in an operated'position although not brought to detonation. Further use of the fuse is impossible without previous disassembly of the latter.

The state of affairs is different, however, when the bayonet connections are brought into the unsafe position before the withdrawal of the two check pins 9 and 10. This is effected by simple rotation of the fuse head 3 relatively to the fuse body 4. .The shearing pin 10 passing through the percussion pin 2 then'comes, as illustrated in Fig. 1 into the left hand corner of the bayonet slot 12. .Since the friction caused by the spring 1 has also to be overcome on relative rotation of the fuse head 3 unintentional setting of the fuse in the unsafe position of its own accord, for example, during transport, is impossible. By said relative rotation the pin 11, which also passes through the percussion pin 2', of the second bayonet connection is rotated so far relatively to the shearing head 3 that it comes over a vertical slot 15 provided, as illustrated in Figs. 4 and 5, in the shearing head. If new the check pin 9 is withdrawn then the fuse is rendered unsafe in so far as the percussion pin 2 can, on Withdrawal from a distance of the pin 10 or on shearing of the latter bypressure on the fuse head 3, be forced inwardly by the action of the spring 1 and cause the fuse cap -7 to explode. The inward movement of the pin 2 is enabled by the vertical slot 15 in which the ends of the pin 11 are adapted to move. As explained above, therefore, striking motion of the percussion pin 2 is not enabled by the withdrawal of one check pin 9, even if the bayonet connection is in the unsafe'position, so long as the other cheek pin 10 has not been withdrawn or sheared by loading of the shearing head 3.

of the fuse. This fuse memes As may be clearly seen from Fig. 3 the first pin 9 is so arranged that it holds the percussion pin 2 only and cannot be sheared by loading of the shearing head 3. The second cheek pin 10 on the other hand is so arranged in the shearing head 3 and the fuse body 4 that it is immediately sheared,.and thus releases the percussion pin 2,011 loading of the shearing head 3 after the withdrawal of the first check pin 9. Due to the presence of the two check pins 9 and 10 it is thus possible to load the fuse as often as desired without operating the same in spite of the bayonet connection being in the unsafe position whilst after withdrawal of the first check pin 9 immediate shearing of the second check pin 10 and thus detonation of the fuse will be caused by loading of the fuse head 3.

To allow of the ready rotation of the fuse head 3 relatively to the fuse body 4, 5 for the purpose of bringing the bayonet connection to the unsafe position the first pin 9 acting merely as a check pin, is guided, as illustrated in Figs. 6 and 7, in a slot 16, of length corresponding to the angle of rotation, in the percussion pin 2. r

Furthermore in order to obtain the smallestpossible length of fuse the end of the percussion pin towards the fuse cap 7 is constructed in the form of a hollow cylinder at the base of which the percussion point 8 is disposed. The support 6 for the fuse cap 7 projects into the hollow cylinder and consequently the fuse has a very inconsiderable height only amounting to about 36 mm. As a result the fuse is prevented from being unintentionally buckled and rendered inoperative by, say, being run over by vehiclesor the like which may readily occur with long fuses due to the production of lateral forces.

As has already been-mentioned above the fuse body consists of screwed together. fuse is screwedby on the fuse cap support 6 into a. mine or the like the part 4 together with the fuse head 3 Consequently when the 1y. In this manner the fuse may be lengthened by, say, two-thirds of its normal length. It is thus readily possible to build up mines under bridges, railwa tracks or other constructions without at rst fitting fuses. The fuses may then be mounted subsequently when occasion demands and may be screwed up by relative rotation of the parts 4 and 5, until the fuse head 3 comes to bear on the constriiction in question.

Figs. 8-10 illustrate another modification operates in essentials precisely sn'mlarly to that described above and it differs only in that it has one safety devlce less; the bayonet connection safety dev ce is omitted. In its stead the up er check pin 9 1s made stronger and can only fie drawn out to a certain predetermined limit, not inthe two parts 4 and 5 may be screwed out of the part 5 subsequentmeans of the thread 17 dicated in the drawing, from the shearing head 3 for the purpose of releasing the percussion pin 2. In contradistinction to the fuse illustrated in Figs. 1-7' therefore the check pin 9 cannot be entirely removed. The reasons for this are as follows: It may happen that the fuse is to remain for a long time in its mounted position and in an unsafe condition. Since the pin 9 cannot be wholly withdrawn the fuse is protec ed against the inward penetration of moisture and therefore against being spoiled from this cause. Furthermore the fuse may at any time also be rendered safe once more, say at night, in a simple manner. It is only necessary to press down somewhat the spring 18 which is arranged on the pin 9 and which has an angle shaped hook portion 19 adapted to rise out of the bore for the pin 9 to prevent unintentional setting of the fuse in the safe condition, and then to reinsert the pin 9 in the fuse head; the fuse is thereupon again in a safe condition for transport and may, if necessary, be used again at another point. The spring 18 is also intended to prevent unintentional falling out of the pin 9, setting the fuse in the unsafe condition, by its upwardly directed pressure on the percussion pin 2 in the inserted position of the pin 9. As contrasted with the first described fuse that illustrated in Figs. 81O has the advantage of being easier to handle. After the withdrawal of the check pin 9 the fuse is detonated either by withdrawal of the second check pin 10 from a distance or by shearing of said pin when the fuse head 3 is loaded.

What I claim is 1. In a fuse of the kind described, a cylindrical casing, a cap covering the upper end of saidcasing and having an outer skirt fitting on the exterior of said casing at said upper end, said casing having an internal flange at its upper end, a second skirt carried by said cap and fitting within said flange, a firing pin having a shank at its upper end fitting within the inner skirt and provided with an outwardly extending flange at its lower end, a compression spring between said flanges, a percussion cap support in said casing in normal spaced relation to said firing pin, and a removable safety and shear pin extending through both skirts, the upper part of the casing and said shank and arranged to hold the head of the cap slightly spaced above the casing when in firing position.

2. In a fuse of the kind described, a cylindrical casing, a cap covering the upper end of said casing and having an outer skirt fitting on the exterior of said casing at said upper end, said casing having an internal flange at its upper end, a second skirt carried by said ca and fitting within said flange, a firing pin aving a shank at its upper end fitting within the inner skirt and provided with an outwardly extending flange at its lower end, a compression spring between said flanges, a percussion cap support in said casing in normal spaced relation to said firing pin, and a removable safety and shear pin extending through both skirts, the upper part of the casing and said shank and arranged to hold the head of the cap slightly spaced above the casing when in firing position, said skirts being provided with circumfercntially extending slots wherethrough said pin passes whereby the cap may be rotated on the casing, the slots in the outer casing each having a vertical upwardly extending portion at one end, said vertical portions being diametrically opposite each other, the slots in the inner skirt being of sufficient width to permit said head to seat on the casing upon the cap being rotated to bring the vertical extensions in alinement with said pin.

3. In a fuse of the kind described, a cylindrical casing, a cap covering the upper end of said casing and having an outer skirt fitting on the exterior of said casing atsaid upper end, said casing having an internal flange at its upper end, a second skirt carried by said cap and fitting within said flange. a firing pin having a shank at its upper end and fitting within said inner skirt, a spring urging said pin to firing position, a percussion cap support in said casing in normal spaced relation to said firing pin, a removable safety and shear pin extending through both skirts, the upper part of the casing and said shank and arranged to hold the head of the cap slightly spaced above the casing when in firing position, said skirts being provided with circumferentially extending slots wherethrough said pin passes whereby the cap may be rotated on the casing, the slots in the outer skirt each having a vertical upwardly extending portion at one end, said vertical portions being diametrically opposite each other, the slots in the inner skirt being of suflicient width to permit the head of the cap to seat on the casing upon the cap being rotated to bring the vertical extensions in alinement with said pin, the slots in the inner skirt each having a downwardly extending portion at one end opening through the bottom of the skirt, said downwardly extending portions being opposite the ends of the slots in the outer skirt which lie remote from the vertical extensions.

4. In a fuse of the kind described, a cylindrical casing, a cap covering the upper end of said casing and havingan outer skirt fit.-

ting on the exterior of said casing at said upper end, said casing having an internal flange at its upper end, a second skirt carried by said cap and fitting within said flange, a firing pin having a shank at its upper end and fitting within said inner skirt, a spring urging said pin to firing position, a percussion cap support in said casing in normal memes spaced relation to said firing pin, a removable safety and shear pin extending through both skirts, the upper part of the casing and said shank and arranged to hold the head of the cap slightly spaced above the casing When in firing position said skirts being provided with circumferent-ially extending slots Wherethrough said pin passes whereby the cap may be rotated on the casing, the slots in the outer skirt eaohhaving a vertical upwardly extending portion at one end, said vertical portions being diametrically opposite each other, the slots in the inner skirt being of sufiicient Width to permit the head of the cap to seat on the casing upon the cap being rotated to bring the Vertical extensions in alinement with said pin, the slots in the inner skirt each having a downwardly ex tending portion at one end opening through the bottom of the skirt, said downwardly extending portions being opposite the ends of the slots in the outer skirt Which lie remote from the vertical extensions, and a second safety pin passing through the slots in the inner skirt and the shank and positioned parallel to and immediately below the first safety pin, whereby the first safety pin may be Withdrawn in safety position of the cap and the second safety pin will act to prevent movement of the firing pin relative to the cap.

In testimony whereof I have signed my name to this specification. I

HANS GRUBER. 

